1. Field of the Invention
The present invention relates to a plasma display panel, and more particularly, to a plasma display panel to require a low power consumption and improve discharge efficiency.
2. Background of the Prior Art
In recent years, there are being actively developed flat panel displays such as Liquid Crystal Display (LCD), Field Emission Display (FED) and Plasma Display Panel (PDP).
PDP displays letter or image including graphic while phosphors emit light by means of ultraviolet rays having wavelength of 147 nm generated during discharge of inert mixture gas such as He+Xe or Ne+Xe. These PDPs have advantages in that they are easily made in a thin and large-sized structure. In addition, since the PDPs have a simplified structure, it is easy to fabricate them. Further, the PDPs have advantages in that they are higher in brightness and light emission efficiency than other flat panel displays. Owing to the above advantages, researches for the PDP are being actively carried out.
Especially, in the three-electrode AC surface discharge type PDP, wall charges are accumulated on the surfaces of the electrodes during discharge and the electrodes are protected from the sputtering that is generated by discharge. So, the three-electrode AC surface discharge type PDP has low voltage driving and long life characteristics.
FIGS. 1 and 2 illustrate the structures of the barrier ribs in the conventional PDPs. Specifically, FIG. 1 shows a stripe type barrier rib structure and FIG. 2 shows a wall type barrier rib structure.
Referring to FIGS. 1 and 2, the PDP has a pair of electrodes, e.g., scan electrodes 12Y and sustain electrodes 12Z, formed on a front substrate 10, and an address electrode formed on a rear substrate 18.
Each of the scan electrodes 12Y and the sustain electrodes 12Z is made of transparent electrode material (Indium Tin Oxide: hereinafter referred to as ITO) to transmit visible light, and includes a transparent electrode 12a and a bus electrode 12b. The transparent electrode 12a is larger in area than the bus electrode 12b. The bus electrode 12b compensates for the resistance of the transparent electrode 12a. A scan signal for scanning a panel and a sustain signal for sustaining discharge are mainly applied to the scan electrodes 12Y, and sustain signal is applied to the sustain electrodes 12Z.
A front dielectric layer 14 and a protective layer 16 are successively laminated on the electrodes 12Y and 12Z formed on the front substrate 10. On the front dielectric layer 14 is accumulated the wall charge generated during plasma discharge. The protective layer 16 protects the front dielectric layer 14 from damages caused by sputtering during plasma discharge and also enhances the emission efficiency of the secondary electrons. The protective layer 16 is usually made of magnesium oxide (MgO).
The address electrodes 12X are formed to cross over the electrodes 12Y and 12Z and are provided with data signals to select discharge cells for display images. A rear dielectric layer 22 is formed on the address electrodes 12X. Barrier ribs 24a and 24b are formed on the rear dielectric layer 22 in parallel with the address electrodes 12X.
A phosphor layer 26 is coated on the surfaces of the rear dielectric layer 22 and the barrier ribs 24a and 24b. The phosphor layer 26 is excited by the ultraviolet rays generated during the plasma discharge to generate one of visible rays of red, green and blue colors. The inert gas for discharge is injected into discharge spaces prepared between the front substrate 10/the rear substrate 18 and the barrier ribs 24a and 24b. The barrier ribs 24a and 24b are formed in parallel with the address electrodes 12X to prevent the ultraviolet rays and the visible rays generated by discharge from leaking into the neighboring discharge cells.
In general, a PDP has an efficiency of 11 m/W, brightness of 400 cd/m2 and power consumption of 300 W. Usually, the PDP for home television (TV) needs to improve the brightness and reduce the power consumption. To meet these requirements, the light emission efficiency of panel should be improved.
The light emission efficiency of a PDP is expressed as the following equation 1:                               η          =                                    π              ⁢                              xe2x80x83                            ⁢              BS                        P                          ,                            Equation        ⁢                  xe2x80x83                ⁢        1            
where B is brightness, S is the area of light emission and P is power consumption.
As expressed in the equation 1, the light emission efficiency is proportional to the brightness B and the area of light emission S but inversely proportional to the power consumption P. Accordingly, to improve the light emission efficiency of the PDP, it is required to elevate the brightness B and reduce the power consumption P.
Until now, the stripe type barrier rib (depicted in FIG. 1) and the wall type barrier rib (depicted in FIG. 2) were described.
The stripe type barrier rib 24a separates the discharge cells in a stripe fashion. The phosphors formed in the discharge cells separated in this manner are arranged in a successive configuration of red, blue and green. Each of the discharge cells separated by the stripe type barrier ribs 24a has a ratio of horizontal length to vertical length of 1:3. Since the horizontal length is shorter than the vertical length, the discharge space is reduced and so the discharge efficiency is lowered. In other words, the stripe type barrier rib 24a is useful to gas evacuation but its light emission efficiency is low due to the small covering area of the phosphors. Also, in the stripe type barrier rib 24a, the visible light is not effectively emitted to the outside of the discharge cell since the occupying area of the phosphors 26 formed on the lower portions of the discharge cells is small.
To overcome the above-described problem, there is proposed a wall type barrier rib 24b in which the shape of discharge cells substantially approaches the square. While this wall type barrier rib 24b enlarges the coated area of the phosphors 26 to elevate the brightness, it has a problem in that the gas evacuation is not easy. To overcome this problem, there is suggested is the PDP having delta type barrier ribs illustrated in FIGS. 3 and 4.
Referring to FIGS. 3 and 4, a discharge cell of the PDP having delta type barrier ribs 24c includes electrodes 12Y and 12Z formed on a front substrate 10 and an address electrode 12X formed on a rear substrate 18. The delta type barrier rib 24c is formed on the rear substrate 18 on which the address electrode 12X is formed, and has discharge cells each surrounded by six faces to form a connection structure of narrow channels 34. The channel 34 makes gas evacuation and gas injection easy.
Each of the electrodes 12Y and 12Z have a transparent electrode 12a made of ITO that has good transparency and a metal electrode 12b to lower the high resistance of the transparent electrode 12a. These electrodes 12Z and 12Y are arranged symmetrically at all discharge cells, and so the metal electrode 12b is located at the center of the transparent electrode 12a unlike the discharge cells of the stripe type barrier ribs and the wall type barrier ribs. Since the metal electrode 12b shields the light that is incident into the discharge cell, the brightness is reduced depending on the shielded light amount. In addition, the delta type barrier rib 24c makes it difficult to secure the discharge space due to a tendency toward the high definition of the PDP, so that the discharge efficiency is reduced. Also, since the discharge area of the transport electrode 12a relates to discharge voltage, the increase of the discharge area causes the discharge voltage necessary for discharge to be increased. As a result, the power consumption is increased and thus the light emission efficiency is lowered. To this end, it is strongly required to reduce the discharge area and maximize the discharge efficiency.
An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.
Accordingly, the present invention is to provide a plasma display panel for forming the transparent electrodes in the direction of a long axis of barrier ribs.
These and other objects and advantages of the invention are achieved by providing a plasma display panel which includes: delta type barrier ribs formed on a rear substrate; scan electrode lines and sustain electrode lines formed on a front substrate in a long axis direction of the delta type barrier ribs; first projection electrodes formed to project from the scan electrode lines alternatively in both directions perpendicular to the scan electrode lines; second projection electrodes formed to project from the sustain electrode lines alternatively and facing the first projection electrodes; first transparent electrodes perpendicularly connected to the first projection electrodes and formed over the neighboring discharge cells of the delta type barrier ribs; second transparent electrodes connected to the second projection electrodes perpendicularly and formed over the neighboring discharge cells of the delta type barrier ribs; and address electrodes formed on a rear substrate in parallel with the first transparent electrodes and the second transparent electrodes and larger at the discharge cells than at the delta type barrier ribs.
It is desired that the first transparent electrodes and the second transparent electrodes include a pair of wings that extend in a short axis direction of the delta type barrier ribs at ends thereof.
It is desired that the first transparent electrodes and the second transparent electrodes include a pair of wings extending in a short axis direction of the delta type barrier ribs at ends thereof; and a center wing extending in the direction of the short axis of the delta type barrier ribs at position facing the delta type barrier ribs.
It is desired that the first transparent electrodes and the second transparent electrodes are formed in the form of a rectangular having a plurality of rectangular or ellipse holes.
According to another aspect of the present invention, a plasma display panel includes: delta type barrier ribs formed on a rear substrate; scan electrode lines and sustain electrode lines formed on a front substrate in a direction of a long axis of the delta type barrier ribs; first projection electrodes formed to project from the scan electrode lines alternatively in both directions perpendicular to the scan electrode lines; second projection electrodes formed to project from the sustain electrode lines alternatively and facing the first projection electrodes; first and second transparent electrodes respectively and perpendicularly connected to the first and second projection electrodes and formed in the form of a rectangular extending to the neighboring discharge cells around the delta type barrier ribs; and address electrodes formed on the rear substrate in parallel with the first transparent electrodes and the second transparent electrodes with an area larger at the discharge cells than at the delta type barrier ribs.
According to further aspect of the present invention, a plasma display panel includes: delta type barrier ribs formed on a rear substrate; scan electrode lines and sustain electrode lines formed on a front substrate in a direction of a long axis of the delta type barrier ribs; first projection electrodes formed to project from the scan electrode lines alternatively in both directions perpendicular to the scan electrode lines; second projection electrodes formed to project from the sustain electrode lines alternatively and facing the first projection electrodes; first and second transparent electrodes respectively and perpendicularly connected to the first and second projection electrodes, including a pair of wings extending in a direction of a short axis of the delta type barrier ribs at ends thereof, and formed extending to the neighboring discharge cells around the delta type barrier ribs; and address electrodes formed on the rear substrate in parallel with the first transparent electrodes and the second transparent electrodes with an area larger at the discharge cells than at the delta type barrier ribs.
According to still aspect of the present invention, a plasma display panel includes: delta type barrier ribs formed on a rear substrate; scan electrode lines and sustain electrode lines formed on a front substrate in a direction of a long axis of the delta type barrier ribs; first projection electrodes formed to project from the scan electrode lines alternatively in both directions perpendicular to the scan electrode lines; second projection electrodes formed to project from the sustain electrode lines alternatively and facing the first projection electrodes; first and second transparent electrodes respectively and perpendicularly connected to the first and second projection electrodes, including a pair of wings extending in a direction of a short axis of the delta type barrier ribs at ends thereof and a center wing extending in the direction of the short axis of the delta type barrier ribs at position facing the delta type barrier ribs, and formed extending to the neighboring discharge cells around the delta type barrier ribs; and address electrodes formed on the rear substrate in parallel with the first transparent electrodes and the second transparent electrodes and larger at the discharge cells than at the delta type barrier ribs.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.